Who shouldn't drink hibiscus tea?

Hibiscus tea works for some but is risky for others. The major risk is taking hibiscus tea if you're on blood pressure or blood sugar medication as it can lower either one to dangerous levels. It's also been known to cause headaches, nausea and dermatitis. Overall, it's important to talk to your doctor before trying hibiscus tea, especially if you are on medication or have any pre-existing health conditions.